Power amplifier module

ABSTRACT

A power amplifier module includes an amplifier that amplifies an input signal and outputs an amplified signal, a matching circuit disposed between an output terminal of the amplifier and a subsequent circuit, a choke inductor having a first end to which a power supply voltage is applied and a second end from which power supply is provided to the amplifier through the output terminal of the amplifier, and a first attenuation circuit disposed between the output terminal of the amplifier and the second end of the choke inductor and configured to attenuate a harmonic component of the amplified signal.

This is a continuation of U.S. patent application Ser. No. 15/586,367filed on May 4, 2017, which claims priority from Japanese PatentApplication No. 2016-100524 filed on May 19, 2016. The content of eachof these applications is incorporated herein by reference in itsentirety.

BACKGROUND

The present disclosure relates to a power amplifier module. A mobileterminal that uses a communication network for cellular phones includesa power amplifier module for amplifying power of a radio-frequency (RF)signal to be transmitted to a base station. In the power amplifiermodule, a resonant circuit is used to attenuate a harmonic component ofan amplified signal to be output from an amplifier (a signal having afrequency that is an integer multiple of the fundamental frequency ofthe amplified signal). For example, Japanese Unexamined PatentApplication Publication No. 10-145147 discloses a configuration in whichharmonic termination circuits (resonant circuits) are disposed betweenan output terminal of an amplifier and an output terminal of ahigh-frequency amplifier circuit.

A matching circuit is typically disposed between an output terminal ofan amplifier and an output terminal of a power amplifier module toprovide impedance matching between the amplifier and the subsequentcircuit. In this configuration, if the matching circuit includes aharmonic termination circuit as disclosed in Japanese Unexamined PatentApplication Publication No. 10-145147, signal loss within the matchingcircuit may increase due to the influence of the frequencycharacteristics of the harmonic termination circuit.

BRIEF SUMMARY

Accordingly, the present disclosure provides a power amplifier modulethat is configured to attenuate harmonic components and to eliminate orreduce the loss of a fundamental component.

A power amplifier module according to embodiments of the presentdisclosure includes an amplifier that amplifies an input signal andoutputs an amplified signal, a matching circuit disposed between anoutput terminal of the amplifier and a subsequent circuit, a chokeinductor having a first end to which a power supply voltage is appliedand a second end from which power supply is provided to the amplifierthrough the output terminal of the amplifier, and a first attenuationcircuit disposed between the output terminal of the amplifier and thesecond end of the choke inductor, the first attenuation circuitattenuating a harmonic component of the amplified signal.

According to embodiments of the present disclosure, it is possible for apower amplifier module to attenuate harmonic components and to eliminateor reduce the loss of a fundamental component.

Other features, elements, characteristics and advantages of the presentdisclosure will become more apparent from the following detaileddescription of embodiments of the present disclosure with reference tothe attached drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates a configuration of a power amplifier module accordingto an embodiment of the present disclosure;

FIG. 2 illustrates a configuration of a power amplifier module accordingto a first comparative example;

FIG. 3 illustrates impedance loci in a matching circuit of the poweramplifier module illustrated in FIG. 1;

FIG. 4A illustrates a simulation result of signal loss in the poweramplifier module illustrated in FIG. 1;

FIG. 4B illustrates an enlarged version of a carrier frequency band insimulation results illustrated in FIG. 4A;

FIG. 5 illustrates a configuration of a power amplifier module accordingto a second comparative example;

FIG. 6A illustrates a simulation result of signal loss in the secondcomparative example;

FIG. 6B illustrates an enlarged version of a carrier frequency band insimulation results illustrated in FIG. 6A;

FIG. 7 illustrates a configuration of a power amplifier module accordingto a third comparative example;

FIG. 8A illustrates a simulation result of signal loss in the thirdcomparative example;

FIG. 8B illustrates an enlarged version of a carrier frequency band insimulation results illustrated in FIG. 8A;

FIG. 9 illustrates a configuration of a power amplifier module accordingto a fourth comparative example;

FIG. 10A illustrates a simulation result of signal loss in the fourthcomparative example;

FIG. 10B illustrates an enlarged version of a carrier frequency band insimulation results illustrated in FIG. 10A;

FIG. 11 illustrates a configuration of a power amplifier moduleaccording to a fifth comparative example; and

FIG. 12 illustrates impedance loci in an attenuation circuit and aharmonic termination circuit.

DETAILED DESCRIPTION

An embodiment of the present disclosure will be described hereinafterwith reference to the drawings. FIG. 1 illustrates a configuration of apower amplifier module 100 according to an embodiment of the presentdisclosure. The power amplifier module 100 is a module that amplifies aradio-frequency (RF) signal (RFin) and outputs the amplified signal(RFout2). The power amplifier module 100 includes, for example, aheterojunction bipolar transistor (HBT) chip 110, a matching circuit120, a choke inductor Lv, a capacitor Cv, and an attenuation circuit130. The configuration of the power amplifier module 100 is not limitedto the configuration illustrated in FIG. 1, and the power amplifiermodule 100 may have any other configuration.

The HBT chip 110 (first chip) is a chip having integrated elementsincluding an HBT. In the following, an HBT is sometimes referred tosimply as a “transistor”. The HBT chip 110 includes a transistor TR anda harmonic termination circuit 140.

The transistor TR (amplifier) has an emitter grounded, a collector(output terminal) connected to a terminal T1, and a base to which an RFsignal RFin is input. An amplified signal RFout1, which is obtained byamplifying the RF signal RFin (input signal), is output from thecollector of the transistor TR. The harmonic termination circuit 140(third attenuation circuit) attenuates a harmonic component (forexample, the second harmonic) included in the amplified signal RFout1.The harmonic termination circuit 140 includes, for example, a capacitorCt and an inductor Lt, which are connected in series. As illustrated inFIG. 1, the harmonic termination circuit 140 has one end connected tothe collector of the transistor TR, and another end grounded.

The configuration of the HBT chip 110 is not limited to theconfiguration illustrated in FIG. 1, and the HBT chip 110 may have anyother configuration. For example, the HBT chip 110 may include aplurality of stages of amplifiers. The HBT chip 110 may further includea bias circuit that supplies a bias current or a bias voltage to thetransistor TR. In addition, the harmonic component to be attenuated bythe harmonic termination circuit 140 is not limited to the secondharmonic and may be a third or higher order harmonic component.Furthermore, the HBT chip 110 may not necessarily include the harmonictermination circuit 140. However, since, among the harmonic componentsincluded in the amplified signal RFout1, the energy of the secondharmonic is particularly high, it is effective to attenuate the secondharmonic at a position close to the collector (output terminal) of thetransistor TR by using the harmonic termination circuit 140. In thisembodiment, furthermore, an HBT is used as a transistor constituting anamplifier; however, the transistor is not limited to a bipolartransistor and may be a field-effect transistor (FET).

The matching circuit 120 is disposed between the transistor TR and thesubsequent circuit (for example, a switch circuit) to match the outputimpedance of the transistor TR and the input impedance of the subsequentcircuit. The matching circuit 120 includes an attenuation circuit 150and a high-pass filter (HPF) 160. The amplified signal RFout1 outputfrom the HBT chip 110 is output as an amplified signal RFout2 throughthe matching circuit 120.

The attenuation circuit 150 (second attenuation circuit) attenuates aharmonic component (for example, the second harmonic) included in theamplified signal RFout1. The attenuation circuit 150 includes, forexample, an inductor L2 (second inductor) and a capacitor C2 (secondcapacitor). The inductor L2 has an end connected to the terminal T1 ofthe HBT chip 110. The capacitor C2 has one end connected to another endof the inductor L2, and another end grounded. The harmonic component tobe attenuated by the attenuation circuit 150 is not limited to thesecond harmonic and may be a third or higher order harmonic component.

The HPF 160 attenuates components having frequencies lower than apredetermined cutoff frequency which are included in the amplifiedsignal RFout1. The cutoff frequency is lower than the frequency of thethird harmonic of the amplified signal RFout1, for example. The HPF 160includes, for example, a capacitor C3 (third capacitor) and an inductorL3 (third inductor). The capacitor C3 has an end connected to the otherend of the inductor L2. The inductor L3 has one end connected to anotherend of the capacitor C3, and another end grounded. The amplified signalRFout2 is output from the other end of the capacitor C3. The capacitorC3 also serves as a direct current (DC) cut capacitor that removes theDC component of the amplified signal RFout1.

The choke inductor Lv has one end to which a power supply voltage Vcc isapplied, and another end from which power supply is provided to thetransistor TR through the collector of the transistor TR. The capacitorCv has one end connected to the one end of the inductor Lv, and anotherend grounded.

The attenuation circuit 130 (first attenuation circuit) attenuates aharmonic component (for example, the third harmonic) included in theamplified signal RFout1. The attenuation circuit 130 is disposed betweenthe other end of the inductor Lv and the collector of the transistor TR.The attenuation circuit 130 includes, for example, an inductor L1 (firstinductor) and a capacitor C1 (first capacitor). The inductor L1 has oneend connected to the collector of the transistor TR via the terminal T1,and another end connected to the other end of the choke inductor Lv. Thecapacitor C1 has one end connected to the other end of the inductor L1,and another end grounded. The inductance of the choke inductor Lv ismuch greater than the inductance of the inductor L1. Hence, the inputimpedance of the choke inductor Lv, as viewed from the other end of theinductor L1, can be regarded as being open in terms of a specificfrequency range. Accordingly, the inductor L1 and the capacitor C1 forma series resonant circuit for attenuating a harmonic component (forexample, the third harmonic) included in the amplified signal RFout1.The harmonic component to be attenuated by the attenuation circuit 130is not limited to the third harmonic and may be the second harmonic or afourth or higher order harmonic component.

The power amplifier module 100 includes the attenuation circuit 130 thatattenuates a harmonic component (for example, the third harmonic). Thisconfiguration allows the power amplifier module 100 to attenuate theharmonic component of the amplified signal RFout1. In the poweramplifier module 100, the attenuation circuit 130 is disposed betweenthe terminal T1 of the HBT chip 110 and the choke inductor Lv ratherthan within the matching circuit 120. This configuration allows thepower amplifier module 100 to eliminate or reduce the loss of afundamental component, compared with a configuration in which a harmonictermination circuit for attenuating a harmonic component (for example,the third harmonic) is disposed within the matching circuit 120.

FIG. 2 illustrates a configuration of a power amplifier module 200according to a first comparative example (hereinafter referred to as thefirst comparative example 200) for comparison with the power amplifiermodule 100. Elements equivalent to those of the power amplifier module100 are assigned equivalent numerals and are not described herein. Thefirst comparative example 200 does not include the attenuation circuit130 of the power amplifier module 100. The first comparative example 200includes a matching circuit 210 in place of the matching circuit 120 ofthe power amplifier module 100. The matching circuit 210 includes anattenuation circuit 220 in place of the HPF 160 in the matching circuit120 of the power amplifier module 100. The matching circuit 210 furtherincludes a capacitor C5.

The attenuation circuit 220 attenuates a harmonic component (forexample, the third harmonic) included in the amplified signal RFout1.The attenuation circuit 220 includes, for example, an inductor L4 and acapacitor C3. The inductor L4 has one end connected to the other end ofthe inductor L2, and another end connected to one end of the capacitorC5. The capacitor C3 has one end connected to the other end of theinductor L4, and another end grounded. An amplified signal RFout2 fromwhich the DC component has been removed is output from another end ofthe capacitor C5.

In the first comparative example 200 illustrated in FIG. 2, theattenuation circuit 220 disposed in the matching circuit 210, instead ofthe attenuation circuit 130 of the power amplifier module 100, canattenuate a harmonic component (for example, the third harmonic)included in the amplified signal RFout1. However, the configuration ofthe power amplifier module 100 enables the power amplifier module 100 tosupport a wider frequency band than that with the configuration of thefirst comparative example 200. A description of this point will be made.

Each of the attenuation circuits 150 and 220 includes an inductorconnected in series with a signal path and a capacitor shunt connectedacross the signal path and is a circuit of a low-pass filter (LPF) type.In contrast, the HPF 160 includes a capacitor connected in series with asignal path and an inductor shunt connected across the signal path andis a circuit of an HPF type.

FIG. 3 illustrates impedance loci in the matching circuit 120 of thepower amplifier module 100 when plotted on a Smith chart. FIG. 3 depictsthe loci of the impedance of the inductor L3, the capacitor C3, thecapacitor C2, and the inductor L2 (on the low-frequency side and thehigh-frequency side) from the center (50Ω) of the Smith chart. Asillustrated in FIG. 3, in the HPF 160 (the capacitor C3 and the inductorL3), which is of the HPF type, the connection between the capacitor C3and the inductor L3 permits a larger movement (change) of the impedanceon the low-frequency side than the impedance on the high-frequency side.In the attenuation circuit 150 (the inductor L2 and the capacitor C2),which is of the LPF type, in contrast, the connection between theinductor L2 and the capacitor C2 permits a larger movement (change) ofthe impedance on the high-frequency side than the impedance on thelow-frequency side. In the matching circuit 120, a combination of thecircuit with a larger movement (change) on the high-frequency side (theattenuation circuit 150) and the circuit of the HPF type (the HPF 160)with a larger movement (change) on the low-frequency side enables themovements of the impedance to be canceled since the change of theimpedance on the HPF side and the change of the impedance on the LPFside are opposite. Thus, the impedance on the low-frequency side and theimpedance on the high-frequency side are combined together into aspecific impedance. In contrast, in the matching circuit 210 in thefirst comparative example 200, the attenuation circuits 150 and 220 areof the LPF type, and the impedance on the high-frequency side changeslargely. Thus, compared with the matching circuit 120 of the poweramplifier module 100, due to their frequency characteristics, theimpedance on the low-frequency side and the impedance on thehigh-frequency side are difficult to combine together into a specificimpedance. Therefore, the matching circuit 120, which is constituted bythe circuit of the LPF type (the attenuation circuit 150) and thecircuit of the HPF type (the HPF 160), makes wider-band impedancematching of the power amplifier module 100 feasible.

FIG. 4A illustrates a simulation result of signal loss within the poweramplifier module 100. In FIG. 4A, the horizontal axis represents thefrequency (GHz) of the RF signal RFin and the vertical axis representssignal loss (dB) within the power amplifier module 100. In thissimulation, the carrier frequency band (the band of the fundamentalfrequency of the carrier wave) is set to be within a range of 2.3 to 2.7GHz. In FIG. 4A, signal loss within a configuration in which theattenuation circuit 130 is excluded from the power amplifier module 100is also illustrated for comparison. As illustrated in FIG. 4A, it isfound that the power amplifier module 100, which includes theattenuation circuit 130, enables the third harmonic to be attenuated inaddition to the second harmonic.

FIG. 4B illustrates an enlarged version of the carrier frequency band(2.3 to 2.7 GHz) in the simulation results illustrated in FIG. 4A. Asillustrated in FIG. 4B, it is found that, within the power amplifiermodule 100, signal loss over the carrier frequency band is substantiallyequivalent to that within the configuration that does not include theattenuation circuit 130.

Also from the simulation results illustrated in FIG. 4A and FIG. 4B, itis found that it is possible for the power amplifier module 100 toattenuate harmonic components and to eliminate or reduce the loss of afundamental component.

FIG. 5 illustrates a configuration of a power amplifier module 500according to a second comparative example (hereinafter referred to asthe second comparative example 500) for comparison with the poweramplifier module 100. Elements equivalent to those of the poweramplifier module 100 are assigned equivalent numerals and are notdescribed herein. The second comparative example 500 does not includethe attenuation circuit 130 of the power amplifier module 100. Thesecond comparative example 500 includes a matching circuit 510 in placeof the matching circuit 120 of the power amplifier module 100. Thematching circuit 510 further includes a capacitor C6 in addition to theattenuation circuit 150 and the HPF 160 in the matching circuit 120 ofthe power amplifier module 100.

The capacitor C6 attenuates a harmonic component (for example, the thirdharmonic) included in the amplified signal RFout1. The capacitor C6 hasone end connected to the terminal T1 of the HBT chip 110, and anotherend grounded.

FIG. 6A illustrates a simulation result of signal loss within the secondcomparative example 500. In FIG. 6A, the horizontal axis represents thefrequency (GHz) of the RF signal RFin and the vertical axis representssignal loss (dB) within the second comparative example 500. In thissimulation, the carrier frequency band (the band of the fundamentalfrequency of the carrier wave) is set to be within a range of 2.3 to 2.7GHz. In FIG. 6A, signal loss within a configuration in which theattenuation circuit 130 is excluded from the power amplifier module 100is also illustrated for comparison. As illustrated in FIG. 6A, it isfound that the second comparative example 500, which includes thecapacitor C6, enables the third harmonic to be attenuated in addition tothe second harmonic.

FIG. 6B illustrates an enlarged version of the carrier frequency band(2.3 to 2.7 GHz) in the simulation results illustrated in FIG. 6A. Asillustrated in FIG. 6B, it is found that, within the second comparativeexample 500, signal loss over the carrier frequency band is greater thanthat within the configuration that does not include the attenuationcircuit 130.

The simulation results illustrated in FIG. 6A and FIG. 6B show thatwhile the second comparative example 500 enables the third harmonic tobe attenuated in addition to the second harmonic, the loss of afundamental component increases. Therefore, also from these simulationresults, it is found that it is possible for the power amplifier module100 to attenuate harmonic components and to eliminate or reduce the lossof a fundamental component, compared with the second comparative example500.

FIG. 7 illustrates a configuration of a power amplifier module 700according to a third comparative example (hereinafter referred to as thethird comparative example 700) for comparison with the power amplifiermodule 100. Elements equivalent to those of the power amplifier module100 are assigned equivalent numerals and are not described herein. Thethird comparative example 700 does not include the attenuation circuit130 of the power amplifier module 100. The third comparative example 700includes a matching circuit 710 in place of the matching circuit 120 ofthe power amplifier module 100. The matching circuit 710 furtherincludes a capacitor C7 in addition to the attenuation circuit 150 andthe HPF 160 in the matching circuit 120 of the power amplifier module100.

The capacitor C7 attenuates a harmonic component (for example, the thirdharmonic) included in the amplified signal RFout1. The capacitor C7 hasone end connected to the other end of the capacitor C3, and another endgrounded.

FIG. 8A illustrates a simulation result of signal loss within the thirdcomparative example 700. In FIG. 8A, the horizontal axis represents thefrequency (GHz) of the RF signal RFin and the vertical axis representssignal loss (dB) within the third comparative example 700. In thissimulation, the carrier frequency band (the band of the fundamentalfrequency of the carrier wave) is set to be within a range of 2.3 to 2.7GHz. In FIG. 8A, signal loss within a configuration in which theattenuation circuit 130 is excluded from the power amplifier module 100is also illustrated for comparison. As illustrated in FIG. 8A, it isfound that the third comparative example 700, which includes thecapacitor C7, enables the third harmonic to be attenuated in addition tothe second harmonic.

FIG. 8B illustrates an enlarged version of the carrier frequency band(2.3 to 2.7 GHz) in the simulation results illustrated in FIG. 8A. Asillustrated in FIG. 8B, it is found that, within the third comparativeexample 700, signal loss over the carrier frequency band is greater thanthat within the configuration that does not include the attenuationcircuit 130.

The simulation results illustrated in FIG. 8A and FIG. 8B show thatwhile the third comparative example 700 enables the third harmonic to beattenuated in addition to the second harmonic, the loss of a fundamentalcomponent increases. Therefore, also from these simulation results, itis found that it is possible for the power amplifier module 100 toattenuate harmonic components and to eliminate or reduce the loss of afundamental component, compared with the third comparative example 700.

FIG. 9 illustrates a configuration of a power amplifier module 900according to a fourth comparative example (hereinafter referred to asthe fourth comparative example 900) for comparison with the poweramplifier module 100. Elements equivalent to those of the poweramplifier module 100 are assigned equivalent numerals and are notdescribed herein. The fourth comparative example 900 does not includethe attenuation circuit 130 of the power amplifier module 100. Thefourth comparative example 900 includes a matching circuit 910 in placeof the matching circuit 120 of the power amplifier module 100. Thematching circuit 910 further includes a capacitor C8 and an inductor L8in addition to the attenuation circuit 150 and the HPF 160 in thematching circuit 120 of the power amplifier module 100.

The capacitor C8 and the inductor L8 constitute a parallel-connectedtank circuit. The tank circuit attenuates a harmonic component (forexample, the third harmonic) included in the amplified signal RFout1.The tank circuit has one end connected to the other end of the capacitorC3, and another end from which the amplified signal RFout2 is output.

FIG. 10A illustrates a simulation result of signal loss within thefourth comparative example 900. In FIG. 10A, the horizontal axisrepresents the frequency (GHz) of the RF signal RFin and the verticalaxis represents signal loss (dB) within the fourth comparative example900. In this simulation, the carrier frequency band (the band of thefundamental frequency of the carrier wave) is set to be within a rangeof 2.3 to 2.7 GHz. In FIG. 10A, signal loss within a configuration inwhich the attenuation circuit 130 is excluded from the power amplifiermodule 100 is also illustrated for comparison. As illustrated in FIG.10A, it is found that the fourth comparative example 900, which includesthe capacitor C8 and the inductor L8, enables the third harmonic to beattenuated in addition to the second harmonic.

FIG. 10B illustrates an enlarged version of the carrier frequency band(2.3 to 2.7 GHz) in the simulation results illustrated in FIG. 10A. Asillustrated in FIG. 10B, it is found that, within the fourth comparativeexample 900, signal loss over the carrier frequency band is greater thanthat within the configuration that does not include the attenuationcircuit 130.

The simulation results illustrated in FIG. 10A and FIG. 10B show thatwhile the fourth comparative example 900 enables the third harmonic tobe attenuated in addition to the second harmonic, the loss of afundamental component increases. Therefore, also from these simulationresults, it is found that it is possible for the power amplifier module100 to attenuate harmonic components and to eliminate or reduce the lossof a fundamental component, compared with the fourth comparative example900.

FIG. 11 illustrates a configuration of a power amplifier module 1100according to a fifth comparative example (hereinafter referred to as thefifth comparative example 1100) for comparison with the power amplifiermodule 100. Elements equivalent to those of the power amplifier module100 are assigned equivalent numerals and are not described herein. Thefifth comparative example 1100 does not include the attenuation circuit130 of the power amplifier module 100. The fifth comparative example1100 includes an HBT chip 1110 in place of the HBT chip 110 of the poweramplifier module 100. The HBT chip 1110 includes a harmonic terminationcircuit 1120 in addition to the transistor TR and the harmonictermination circuit 140 on the HBT chip 110 of the power amplifiermodule 100.

The harmonic termination circuit 1120 attenuates a harmonic component(for example, the third harmonic) included in the amplified signalRFout1. The harmonic termination circuit 1120 includes, for example, acapacitor C9 and an inductor L9, which are connected in series. Asillustrated in FIG. 11, the harmonic termination circuit 1120 has oneend connected to the collector of the transistor TR, and another endgrounded.

FIG. 12 illustrates the loci of the impedance of a harmonic (forexample, the third harmonic) in the attenuation circuit 130 and theharmonic termination circuit 1120. In the power amplifier module 100,external wiring of the HBT chip 110 is present between the terminal T1of the HBT chip 110 and the inductor L1 of the attenuation circuit 130.This wiring is longer than internal wiring of the HBT chip 110 and has acomparatively large parasitic inductance. As illustrated in FIG. 12, inthe attenuation circuit 130 of the power amplifier module 100, due tothis parasitic inductance, the impedance of a harmonic (for example, thethird harmonic) when a resonance point is set at the frequency band ofthe harmonic (for example, the third harmonic) is adjusted to achievethe open condition. In the fifth comparative example 1100, in contrast,since the harmonic termination circuit 1120 is included in the HBT chip1110, the wiring has a very small parasitic capacitance and a very smallparasitic inductance. In the fifth comparative example 1100, therefore,as illustrated in FIG. 12, the locus of the impedance of a harmonic (forexample, the third harmonic) changes and it is difficult to adjust theimpedance of the harmonic (for example, the third harmonic) to achievethe open condition. In the power amplifier module 100, accordingly, theattenuation circuit 130 disposed between the HBT chip 110 and the chokeinductor Lv enables the impedance of the harmonic component to be set tothe open condition.

Here, the impedance at the attenuation frequency (for example, thesecond harmonic) of the harmonic termination circuit 140 is set to theshort condition and the impedance at the attenuation frequency (forexample, the third harmonic) of the attenuation circuit 130 is set tothe open condition, thereby making operation of a class-F amplifierfeasible.

An embodiment of the present disclosure has been described. In the poweramplifier module 100, the attenuation circuit 130 is disposed betweenthe output terminal of the transistor TR and the choke inductor Lv. Thisconfiguration allows the power amplifier module 100 to attenuate aharmonic component of the amplified signal RFout1. In addition, thepower amplifier module 100 can eliminate or reduce the loss of afundamental component, compared with a configuration in which a harmonictermination circuit for attenuating a harmonic component (for example,the third harmonic) is disposed in the matching circuit 120.

In the power amplifier module 100, furthermore, the matching circuit 120includes the attenuation circuit 150 that attenuates the second harmonicof the amplified signal RFout1. This configuration allows the poweramplifier module 100 to attenuate the third harmonic by using theattenuation circuit 130 and to attenuate the second harmonic by usingthe attenuation circuit 150.

In the power amplifier module 100, furthermore, the matching circuit 120may further include the HPF 160 that has a cutoff frequency lower thanthe fundamental frequency of the amplified signal RFout1.

In the power amplifier module 100, furthermore, the HBT chip 110includes the harmonic termination circuit 140 that attenuates the secondharmonic. This configuration allows the second harmonic having highenergy to be effectively attenuated at a position close to the collector(output terminal) of the transistor TR.

In the power amplifier module 100, furthermore, the transistor TR isdefined on the HBT chip 110, whereas the matching circuit 120, the chokeinductor Lv, and the attenuation circuit 130 are located outside the HBTchip 110. Thus, as illustrated in FIG. 12, due to the influence of theparasitic inductance of wiring from the terminal T1 of the HBT chip 110to the inductor L1, the impedance of a harmonic (for example, the thirdharmonic) when a resonance point is set at the frequency band of theharmonic (for example, the third harmonic) can be adjusted to achievethe open condition (class-F). This configuration enables the poweramplifier module 100 to perform a class-F operation.

The embodiment described above is intended for easy understanding of thepresent disclosure, and it is not intended to construe the presentdisclosure in a limiting fashion. Various modifications and improvementscan be made to the present disclosure without departing from the gist ofthe present disclosure, and equivalents thereof are also included in thepresent disclosure. That is, the embodiment may be appropriatelymodified in design by those skilled in the art, and such modificationsalso fall within the scope of the present disclosure so long as themodifications include the features of the present disclosure. Forexample, the elements included in the embodiment and the arrangement,materials, conditions, shapes, sizes, and the like thereof are notlimited to those described in the illustrated examples but can bemodified as appropriate. In addition, the elements included in theembodiment can be combined as much as technically possible, and suchcombinations of elements also fall within the scope of the presentdisclosure so long as the combinations of elements include the featuresof the present disclosure.

While preferred embodiments of the disclosure have been described above,it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the disclosure. The scope of the invention, therefore, isto be determined solely by the following claims.

What is claimed is:
 1. A power amplifier module comprising: an amplifierthat amplifies an input signal and outputs an amplified signal from anoutput terminal; a matching circuit disposed between the output terminalof the amplifier and a subsequent circuit; a choke inductor, wherein apower supply voltage is applied to a first end of the choke inductor;and a first attenuation circuit disposed between the output terminal ofthe amplifier and a second end of the choke inductor, the firstattenuation circuit attenuating a second harmonic of the amplifiedsignal, wherein: the first attenuation circuit includes: a firstinductor, wherein a first end of the first inductor is connected to theoutput terminal of the amplifier and a second end of the first inductoris connected to the second end of the choke inductor, and a firstcapacitor, wherein a first end of the first capacitor is connected tothe second end of the first inductor and a second end of the firstcapacitor is grounded, the matching circuit includes: a secondattenuation circuit that attenuates frequencies greater than afundamental frequency of the amplified signal; and a filter, and thesecond attenuation circuit is a low pass filter including: a secondinductor, wherein a first end of the second inductor is connected to theoutput terminal of the amplifier and a second end of the second inductoris connected to the filter, and a second capacitor, wherein a first endof the second capacitor is connected to a second end of the secondinductor and a second end of the second capacitor is grounded.
 2. Apower amplifier module comprising: an amplifier that amplifies an inputsignal and outputs an amplified signal from an output terminal; amatching circuit disposed between the output terminal of the amplifierand a subsequent circuit; a choke inductor, wherein a power supplyvoltage is applied to a first end of the choke inductor; and a firstattenuation circuit disposed between the output terminal of theamplifier and a second end of the choke inductor, the first attenuationcircuit attenuating a third harmonic of the amplified signal, wherein:the first attenuation circuit includes: a first inductor, wherein afirst end of the first inductor is connected to the output terminal ofthe amplifier and a second end of the first inductor is connected to thesecond end of the choke inductor, and a first capacitor, wherein a firstend of the first capacitor is connected to the second end of the firstinductor and a second end of the first capacitor is grounded, thematching circuit includes: a second attenuation circuit that attenuatesfrequencies greater than a fundamental frequency of the amplifiedsignal; and a high-pass filter having a cutoff frequency lower than thefundamental frequency of the amplified signal, and the secondattenuation circuit is a low pass filter including: a second inductor,wherein a first end of the second inductor is connected to the outputterminal of the amplifier and a second end of the second inductor isconnected to the high-pass filter, and a second capacitor, wherein afirst end of the second capacitor is connected to a second end of thesecond inductor and a second end of the second capacitor is grounded. 3.The power amplifier module according to claim 1, wherein the amplifieris embodied on a first chip, and wherein the matching circuit, the chokeinductor, and the first attenuation circuit are not embodied on thefirst chip.
 4. The power amplifier module according to claim 2, whereinthe amplifier is embodied on a first chip, and wherein the matchingcircuit, the choke inductor, and the first attenuation circuit are notembodied on the first chip.
 5. The power amplifier module according toclaim 3, further comprising: a third attenuation circuit that attenuatesa third harmonic of the amplified signal, wherein the third attenuationcircuit is embodied on the first chip.
 6. The power amplifier moduleaccording to claim 4, further comprising: a third attenuation circuitthat attenuates a second harmonic of the amplified signal, wherein thethird attenuation circuit is embodied on the first chip.
 7. The poweramplifier module according to claim 1, further comprising: a thirdattenuation circuit that attenuates a third harmonic of the amplifiedsignal.
 8. The power amplifier module according to claim 2, furthercomprising: a third attenuation circuit that attenuates a secondharmonic of the amplified signal.
 9. The power amplifier moduleaccording to claim 7, wherein the third attenuation circuit comprises acapacitor and an inductor connected in series between the outputterminal of the amplifier and ground.
 10. The power amplifier moduleaccording to claim 8, wherein the third attenuation circuit comprises acapacitor and an inductor connected in series between the outputterminal of the amplifier and ground.